Clamp



FIG. 1 is a side elevational view showing our new design for a clamp;

FIG. 2 is an end elevational view taken from the right of FIG. 1;

FIG. 3 is an end elevational view taken from the left of FIG. 1;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a perspective view thereof, in the open position.

The ornamental design for a clamp, substantially as shown and described.